Tests and diagnosis

LABORATORY FINDINGS

By definition, lab results for HE patients must show elevated thyroid antibodies – including anti-thyroid peroxidase antibodies (anti-TPO), anti-thyroid microsomal antibodies (anti-M), and/or antithyroglobulin antibodies (anti-Tg).  Notably, however, studies show that the titre (concentration) of elevated antibodies does not correlate with the severity of symptoms. The presence of significantly elevated thyroid antibody levels is considered to be merely a marker of HE, not the cause of the patient’s symptoms. Although testing for elevated antibodies is usually based on serum, these elevated antibody levels are occasionally also present in cerebral spinal fluid (CSF) as well.

HESA  interviewed neurologist Dr. Elzbieta Wirkowski and asked, “What criteria do you use to
recognize HE in clinical practice?


Dr. Wirkowski:
I have seen a wide variety of clinical presentations in HE, and now routinely screen both my hospital and clinic patients for antithyroid antibodies. The profile that would trigger me to consider a course of immunotherapy would be a patient with a relatively normal thyroid function test, highly elevated thyroid antibody levels, and unexplained neurological or psychiatric symptoms. A positive response to immunotherapy would further support the diagnosis.

 

Recently, a number of scientists have studied serum autoantibodies against the NH2-terminal of a-enolase (NAE), which appear to hold promise as a specific diagnostic marker for HE, although this research is limited and tests for these autoantibodies are only available from a handful of laboratories in the world.

Learn more here:

http://www.ncbi.nlm.nih.gov/pubmed/19363998

http://www.ncbi.nlm.nih.gov/pubmed/23196576

EEG

The electroencephalogram studies of HE patients are usually abnormal (up to 90% of cases), but they are almost always non-diagnostic findings. The most common findings are diffuse or generalized slowing, or frontal intermittent rhythmic delta activity (FIRDA). Prominent triphasic waves, focal slowing, epileptiform abnormalities, photoparoxysmal and photomyogenic responses are occasionally seen.

MEDICAL IMAGING

Magnetic resonance imaging (MRI) and computed tomography (CT) scans are frequently normal in those with HE/SREAT. Single-photon emission computed tomography (SPECT) scans often disclose hypoperfusion, and positron emission tomography (PET) scans often disclose hypometabolism.  The results of PET scans, in particular, are often a deciding factor in confirming the diagnosis.

 

Last edited by Web Team on June 20th, 2016